Walls served in the pastoral ministry at Cleveland in Rowan County (1905–7), Lincolnton (1908–10), and Salisbury (1910–13). While officiating in Louisville, Ky., between 1913 and 1920, he built Broadway Temple. Back in North Carolina between 1920 and 1924 he was at Charlotte as editor of the Star of Zion , the official organ of the African Methodist Episcopal church. In Indianapolis in 1924 he was elected bishop and served as senior bishop from 1951 to 1968.

Walls was the author of Wisdom for the Times, What Youth Wants, The Negro in Business and Religion, Joseph Charles Price: Education and Race Leader, The Romance of a College, The Dreams of Youth, Living Essentials of Methodism, Harriet Tubman , and The African Methodist Episcopal Church: Reality of the Black Church.

During the period 1941–73 he was chairman of the trustees of Livingstone College and of the Harriet Tubman Foundation; vice-president of the National Association for the Advancement of Colored People; and a member of the World Sunday School Association, National Council of Churches of Christ in America, and American Bible Society (advisory council, 1941–70). He was also a member of the American Academy of Political Science, Phi Beta Sigma, the Masonic Order, the Odd Fellows, and the Elks.

On 6 Dec. 1956 he married Dorothy L. Jordan. In 1958 he founded Camp Dorothy Walls in Black Mountain. At the time of his death his home and office were in Yonkers, N.Y. Interment was in a family crypt in Lincoln Cemetery, Chicago. Portraits of him are in the Walls Center, Hood Theological Seminary Building, Salisbury; Heritage Building, Livingstone College; and administration building, Camp Dorothy Walls.

References:

Emory S. Bucke, ed., The History of American Methodism , vol. 3 (1964)